Poly hydrodynamic properties

Koleske, J. V., and Lundberg, R. D., Lactone polymers. II. Hydrodynamic properties and unperturbed dimensions of poly-e-caprolactone, J. Polym. Sci., Part A-2. 7, 897-907, 1969. 

That dendrimers are unique when compared with other architectures is confirmed by an investigation on porphyrin core dendrimers and their isomeric linear analogues [63]. The isomers displayed dramatically different hydrodynamic properties, crystallinity, and solubility characteristics when compared to those of their dendritic analogues, and photophysical studies showed that energy transfer from the poly(benzylether) backbone to the core was more efficient in the dendrimer because of the shorter distance between the donor units and the acceptor core. 

Poly(/ -phenylethyl isocyanide) was similarly prepared and fractionated (14). A comparison between the hydrodynamic properties of poly(/T and poly(a-phenylethyl isocyanide) showed, that while the latter was characterized by its intrinsic lack of molecular flexibility, the former was relatively a flexible chain. This was manifested in the values estimated for the shape factor and the radius of gyration. Accordingly, two general conformations in dilute solution are ascribed to poly(phenylethyl isocyanides) a nearly rigid, rodlike helix to poly(a-phenyl-ethyl isocyanide), and an undulating, more randomly orienting chain to poly(/l-phenylethyl isocyanide). 

There is a substantial body of work using dynamic light scattering to probe the hydrodynamic properties of poly(oxyethylene)-based block copolymers in aqueous solution. The work of Brown and co-workers has been reviewed by... 

The points in Fig. 24 represent the experimental values of A for a ladder poly-dichlorophenylsfloxane and cellulose carbanilate For both polymers the experimental data are in agreement with theoretical Curve 4 corresponding to the value of d/A = 0.5 for a kinetically flexible chain polymer. This qualitatively demonstrates that the hydrodynamic properties of the molecules of these two polymers at low X differ from those of an infinitely thin worm-like model. However, to obtain quantitative agreement between theory and experimental data according to Curve 4 in Fig. 24, A/d should be equal to 2 — a reasonable value for many flexible-chain polymers not realistic for such r d-chain polymers as ladder polysiloxanes or cellulose ethers and esters. 

MAT Matsuo, K., Stockmayer, W.H., and Bangerter, F., Conformational properties of poly(l-octadecene/maleic anhydride) in solution, Macro/wo/ecw/ei, 18, 1346, 1985. 1985MIN Minsker, K.S., Panchesnikova, R.B., Monakov, Yu.B., and Zaikov, G.E., Thermodynamic and hydrodynamic properties of chlorine-containing carbochain polymers in solutions, Eur. Polym. J., 21, 981, 1985. 

Bohdanecky, M., Bazilova, H. and Kopecek, J., 1974. Poly[N-(2-hydroxypropyl) methacrylamide] - II Hydrodynamic properties of dilute solutions. European Polymer Journal, 10(5), 405-410. 

LIGHT SCAHERING AND HYDRODYNAMIC PROPERTIES OF POLY /TERTBUTYL METHACRYLATE/. 

Kato, T., Miyaso, K., Noda, I., Fujimoto, T., and Nagasawa, M., 1970. Thermodynamic and hydrodynamic properties of linear polymer solutions, i. Light scattering of monodisperse poly(a -inethylstyrene), Macromolecules, 3, 777-786. 

Hyperbranched poly(ethyl methacrylate)s prepared by the photo-initiated radical polymerization of the inimer 13 were characterized by GPC with a lightscattering detector [51]. The hydrodynamic volume and radius of gyration (i g) of the resulting hyperbranched polymers were determined by DLS and SAXS, respectively. The ratios of Rg/R are in the range of 0.75-0.84, which are comparable to the value of hard spheres (0.775) and significantly lower than that of the linear unperturbed polymer coils (1.25-1.37). The compact nature of the hyperbranched poly(ethyl methacrylate)s is demonstrated by solution properties which are different from those of the linear analogs. 

The solution properties of dendrigraft polybutadienes are, as in the previous cases discussed, consistent with a hard sphere morphology. The intrinsic viscosity of arborescent-poly(butadienes) levels off for the G1 and G2 polymers. Additionally, the ratio of the radius of gyration in solution (Rg) to the hydrodynamic radius (Rb) of the molecules decreases from RJRb = 1.4 to 0.8 from G1 to G2. For linear polymer chains with a coiled conformation in solution, a ratio RJRb = 1.48-1.50 is expected. For rigid spheres, in comparison, a limiting value RJRb = 0.775 is predicted. 

Hydrodynamic radii of poly(benzyl ether) dendrimers are shown in Fig. 5. Data for monodendrons with a hydroxyl focal group and tridendrons fall on the same curve. The value of the exponent v in Eq. (4) is 0.46 of low MW. At high MW it is 0.26 [48]. Data on low MW linear polystyrene in benzene [74] have been included in Fig. 5 for comparison. They highlight the little difference in the actual values of the hydrodynamic radii of linear polystyrene and low MW poly(benzyl ether) dendrimers. Deviations are observed only when MW>5xl03. Furthermore, the MW dependence of the radii of polystyrene and poly(benzyl ether) dendrimers are the same at low MW. This indicates that it remains impossible to draw major conclusions about the conformation of the low MW dendrimers from their global properties. The low values of the hydrodynamic radii of the high MW dendrimers, on the other hand, attest to their compact conformation. A similar transition to more compact dendrimers has recently been shown in a direct comparison of linear and dendritic poly(benzyl ethers) [75]. 

The ODN adsorption onto cationic microgel poly(N-isopropylacrylamide) particles was reported to be dramatically affected by the salinity of the incubation medium [9] as illustrated in Fig. 6. The observed result was related to (i) the reduction in attractive electrostatic interactions between ODN molecules and the adsorbent and (ii) the drastic effect of ionic strength on the physico-chemical properties of such particles [17, 27]. In fact, the hydrodynamic size, the swelling ability, the electrokinetic properties, and the colloidal stability are dramatically affected by pH, salt concentration, and the medium temperature [27]. 

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